Chiropractic care

Since the beginnings of the chiropractic profession in the United States in 1895, there has been continued growth and interest in this therapeutic option. By the late 1990s, of the 42% of individuals using at least one form of alternative therapy within the past 12 months, 11.1% received chiropractic care. Furthermore, nearly 8% of adults and 2.8% of children received chiropractic or osteopathic manipulative therapy in the prior 12 months.

An important principle of chiropractic care involves functional reactivation of the patient. Whereas spinal manipulative therapy (SMT) remains a central feature of chiropractic care, this modality may be used in combination with rehabilitative exercises, ice, heat, electric stimulation, ultrasound, and encouragement of healthy lifestyle modifications. During the course of treatment, the gradual return to activity is encouraged. Ongoing reassessment helps ensure a path toward optimal recovery.

The goals of SMT are to restore dysfunctional joint mechanics and to reduce mechanical stress on the adjacent tissues, thereby reducing pain. Three types of SMT have been described, including unloaded spinal motion, manual repetitive oscillations, and high velocity low amplitude (HVLA) manipulation. Unloaded spinal motion involves continuous passive motion with motorized tables and manual application of flexion-distraction techniques. HVLA manipulation is performed by delivering a quick, impulse-like thrust within a joint’s range of motion. The chiropractor may choose a specific SMT technique considering such factors as the patient’s age, stature, and diagnosis.

Various theories have attempted to explain the benefits of chiropractic manipulation. Examples include the release of plica or entrapped synovial folds, the relaxation of hypertonic muscle by sudden stretch, the disruption of articular or periarticular adhesions, and the restoration of normal motion to displaced joints or vertebral segments. The biomechanics of chiropractic manipulation have been well described by Triano. Indications for SMT include focal tenderness to palpation, abnormal tissue tone, symptoms reproduced with provocative testing, and joint dysfunction or reduced mobility. Contraindications for SMT are listed in Box 1 , including instability, infection, myelopathy, and so forth.

Research has shown short-term treatment effect of SMT with exercise. A 2004 Cochrane review of mechanical neck disorders reported that mobilization and/or manipulation combined with exercise compared with no treatment led to improved function, pain reduction, and perceived effect. A subsequent review of subacute and chronic neck pain reported that the combination of mobilization, manipulation, and exercise demonstrated greater short-term pain relief and quality of life improvements than exercise alone. Greater short-term pain reduction was also achieved in patients with acute whiplash with the combination of chiropractic treatment and exercise compared with traditional care, defined as any two of the following: cervical collar, advice, or pain medication. Radicular symptoms were not assessed. Results from The Bone and Joint Decade (2000–2010) Task Force on Neck Pain and Associated Disorders showed education, mobilization, and exercise to be more efficacious than usual care or physical modalities for whiplash-associated disorders.

Recent reviews have also demonstrated some benefits of SMT for neck disorders when used alone. A 2010 Cochrane review demonstrated “low-quality” evidence that neck manipulations for acute or chronic cervical conditions reduce pain in comparison to controls. In addition, “very low to low-quality” evidence exists that thoracic spine manipulation alone provides immediate reduction in acute neck pain or whiplash symptoms. Neck pain can be related to aberrant thoracic spine biomechanics, such as decreased thoracic spine mobility. Thrust mobilization or manipulation showed greater short-term reduction in neck pain and disability than non-thrust technique.

The most common side-effects of manipulation are generally benign and self-limited. In a prospective survey of 1058 patients undergoing 4712 treatments, the most common side-effects included local discomfort (53%), headache (12%), tiredness (11%), and radiating discomfort (10%). These effects tended to occur within 4 hours of treatment and were characterized as “mild” or “moderate” in the majority of patients. The majority experienced resolution within 24 hours without serious complications. In a systematic review of SMT for neck pain, side-effects were also benign and transient, including radicular symptoms, headache, or exacerbation of neck pain. The risk of minor symptoms appeared to be greater with manipulation versus mobilization in the report from the Bone and Joint Decade Task Force. The risk of vertebrobasilar artery (VBA) stroke has been estimated as 1 in 200,000 to 1 in several million. A case-control study demonstrated that the risk of VBA stroke associated with chiropractic care was not significantly different than for primary care practitioners.

Functional reactivation of the patient focuses on the patient’s symptoms; dysfunction such as impairment, abilities, and participation in vocation and recreational activities; and distress. The goals of functional reactivation are to avoid inactivity, which can result in a deconditioned state, and to encourage a gradual, safe return to activities. Manual therapy, including SMT, is an integral part of chiropractic care that may be used alone or in combination with rehabilitative exercise, ice or heat, electric stimulation and ultrasound, and modification of lifestyle factors. The decision to apply SMT for the management of neck pain is a multifactorial process based on history, physical examination, and clinical assessment of the benefit to risk relationship in the context of patient preference.

Acupuncture

Acupuncture involves the insertion of needles into the body to achieve a treatment effect. Needle types and sizes vary, as do the techniques and theories behind their application. In the classical context, needles are inserted into well-defined, anatomic points on the body with the goal of influencing and normalizing the circulation of chi energy. The Chinese character for chi (also spelled qi) is translated as “rice vapor,” and represents an energy gleaned from digested food and inspired air. Each person is bestowed with a certain amount of original energy at birth as well. Depending on the subtype of chi, it can flow around the body’s surface to defend against external pathogens, along deeper channels or meridians, or from organ to organ in a cyclical pattern. Any imbalances in this flow, whether due to deficiency, excess, or blockage of chi, can result in disease states.

Using acupuncture needles, deficient chi can be tonified, excess chi can be dispersed, and obstructed chi can be dispelled with a series of treatments. Tonification of chi begins by inserting needles along the acupuncture points involving the deficient meridian or organ. Needle insertion is followed by one or more methods of tonification, including manipulating the needles manually, holding a burning, glowing moxa herb ( Artemmisia vulgaris ) near the inserted needles, or by applying low frequency (eg, 4 Hz) electrical stimulation via electrodes clipped to the needles. Dispersion of excess chi can be accomplished by leaving the inserted needles in place undisturbed. Obstructions in the flow of chi can be dispelled by inserting needles along the channel before and after the obstruction. High-frequency electrical stimulation can be applied to augment the effect. Some practitioners may also use herbal medicines, either alone or concurrent with acupuncture treatments, to further influence and harmonize chi.

Acupuncture can employ other paradigms besides influencing chi flow through channels and meridians. Ah Shi points, which are defined by the site of maximal tenderness to palpation rather than by anatomic landmarks, can be needled with the goal of reducing pain. The Japanese surface release technique involves insertion of numerous superficial needles over the affected area, with the idea that the effect penetrates to deeper levels. In auricular acupuncture and Korean hand acupuncture, the body as a whole is represented somatotopically on the ears or the hands, respectively. Local needles inserted into these somatotopic microsystems are thought to have therapeutic effects on the part of the body that is represented at the needle tip. These microsystems can be used alone or at the same time as other treatments to enhance the overall effect.

The heterogeneity of acupuncture interventions and difficulty in blinding present a challenge for reviewing the use of acupuncture for mechanical neck disorders (MND). Birch and Jamison (1998) compared Japanese-style shallow needling of relevant points with sham treatment needling irrelevant points in patients with mechanical neck disorders. A significant treatment benefit was measured. White and colleagues (2000) compared an acupuncture treatment involving needle insertion and stimulation to a sham treatment without needle stimulation and again found a treatment benefit measured at the end of the treatment. However, while showing a clinical effect in favor of acupuncture for MNDs, these studies scored at most 2/5 on the validated Jadad 1996 criteria for methodological quality.

A randomized, controlled trial examining standardized acupuncture needle points versus control points for neck and shoulder pain by He and colleagues (2004) showed no significant effect on pain intensity until 6 to 7 treatments were completed. The investigators concluded that 8 to 10 acupuncture treatments should be given within a few weeks for relief of neck and shoulder pain. In this study, the treatment group had less intense pain than the control group at 3-year follow-up, but not at 6-month follow-up. The investigators surmised the duration of the treatment effect was probably due to breaking the patient’s chronic pain cycle, rather than the acupuncture treatment effect persisting for 3 years. In addition, the lack of significant effect at 6-month follow-up may have been due to the persistence of a placebo effect on the control group at 6-months, which was not as robust at 3 years.

Acupuncture for MNDs has also been studied in comparison to nonsham controls. Coan and colleagues (1982) showed that acupuncture is more effective at pain relief than a wait-list control for patients with chronic mechanical neck pain and radicular symptoms with Jadad score 3/5. Irnich and colleagues (2001) showed acupuncture to be significantly better than massage for MNDs at short-term follow-up (<3 months) with Jadad score 2/5. A meta-analysis of three trials performed by The Cochrane Collaboration showed moderate evidence (three trials, 338 participants) that acupuncture is more effective than inactive treatment for pain relief for patients with chronic MND measured at short-term follow up. In the intermediate (3–12 months) and long-term follow-up categories (>12 months) in this Cochrane review, a single high-quality but underpowered study compared acupuncture with sham and showed no effect.

A cohort study by Blossfeldt (2004) showed an overall success rate of 68% of acupuncture for chronic neck pain, with success defined as 50% or greater improvement of pain at the completion of three or more treatments. However, the study was not blinded, had no formal inclusion or exclusion criteria, did not include a control group, and treatments were individualized rather than standardized. Although Blossfeldt’s study does not prove a treatment effect of acupuncture for chronic neck pain, it is an example of a relatively high level of self-reported patient improvement for a low-risk treatment. Of the 172 patients Blossfeldt treated, only two had complications, including one skin reaction and one migraine headache.

Acupuncture is a relatively safe modality for mechanical neck pain. A systematic review on the safety of acupuncture by Ernst and White 2001 showed the most common adverse events were needle pain (1%–45%), fatigue (2%–41%), and bleeding (0.03%–38%). The incidences of syncope and feeling faint ranged from 0% to 0.3%. Pneumothorax was rare, occurring only twice in nearly a quarter of a million treatments. Overall, acupuncture for mechanical neck disorders is relatively safe. Some evidence exists that it has a beneficial clinical effect for pain relief in the short-term. Further studies are needed to clarify the possible long-term effects and to examine which treatment strategies work best for various cervical conditions.

Acupuncture

Acupuncture involves the insertion of needles into the body to achieve a treatment effect. Needle types and sizes vary, as do the techniques and theories behind their application. In the classical context, needles are inserted into well-defined, anatomic points on the body with the goal of influencing and normalizing the circulation of chi energy. The Chinese character for chi (also spelled qi) is translated as “rice vapor,” and represents an energy gleaned from digested food and inspired air. Each person is bestowed with a certain amount of original energy at birth as well. Depending on the subtype of chi, it can flow around the body’s surface to defend against external pathogens, along deeper channels or meridians, or from organ to organ in a cyclical pattern. Any imbalances in this flow, whether due to deficiency, excess, or blockage of chi, can result in disease states.

Using acupuncture needles, deficient chi can be tonified, excess chi can be dispersed, and obstructed chi can be dispelled with a series of treatments. Tonification of chi begins by inserting needles along the acupuncture points involving the deficient meridian or organ. Needle insertion is followed by one or more methods of tonification, including manipulating the needles manually, holding a burning, glowing moxa herb ( Artemmisia vulgaris ) near the inserted needles, or by applying low frequency (eg, 4 Hz) electrical stimulation via electrodes clipped to the needles. Dispersion of excess chi can be accomplished by leaving the inserted needles in place undisturbed. Obstructions in the flow of chi can be dispelled by inserting needles along the channel before and after the obstruction. High-frequency electrical stimulation can be applied to augment the effect. Some practitioners may also use herbal medicines, either alone or concurrent with acupuncture treatments, to further influence and harmonize chi.

Acupuncture can employ other paradigms besides influencing chi flow through channels and meridians. Ah Shi points, which are defined by the site of maximal tenderness to palpation rather than by anatomic landmarks, can be needled with the goal of reducing pain. The Japanese surface release technique involves insertion of numerous superficial needles over the affected area, with the idea that the effect penetrates to deeper levels. In auricular acupuncture and Korean hand acupuncture, the body as a whole is represented somatotopically on the ears or the hands, respectively. Local needles inserted into these somatotopic microsystems are thought to have therapeutic effects on the part of the body that is represented at the needle tip. These microsystems can be used alone or at the same time as other treatments to enhance the overall effect.

The heterogeneity of acupuncture interventions and difficulty in blinding present a challenge for reviewing the use of acupuncture for mechanical neck disorders (MND). Birch and Jamison (1998) compared Japanese-style shallow needling of relevant points with sham treatment needling irrelevant points in patients with mechanical neck disorders. A significant treatment benefit was measured. White and colleagues (2000) compared an acupuncture treatment involving needle insertion and stimulation to a sham treatment without needle stimulation and again found a treatment benefit measured at the end of the treatment. However, while showing a clinical effect in favor of acupuncture for MNDs, these studies scored at most 2/5 on the validated Jadad 1996 criteria for methodological quality.

A randomized, controlled trial examining standardized acupuncture needle points versus control points for neck and shoulder pain by He and colleagues (2004) showed no significant effect on pain intensity until 6 to 7 treatments were completed. The investigators concluded that 8 to 10 acupuncture treatments should be given within a few weeks for relief of neck and shoulder pain. In this study, the treatment group had less intense pain than the control group at 3-year follow-up, but not at 6-month follow-up. The investigators surmised the duration of the treatment effect was probably due to breaking the patient’s chronic pain cycle, rather than the acupuncture treatment effect persisting for 3 years. In addition, the lack of significant effect at 6-month follow-up may have been due to the persistence of a placebo effect on the control group at 6-months, which was not as robust at 3 years.

Acupuncture for MNDs has also been studied in comparison to nonsham controls. Coan and colleagues (1982) showed that acupuncture is more effective at pain relief than a wait-list control for patients with chronic mechanical neck pain and radicular symptoms with Jadad score 3/5. Irnich and colleagues (2001) showed acupuncture to be significantly better than massage for MNDs at short-term follow-up (<3 months) with Jadad score 2/5. A meta-analysis of three trials performed by The Cochrane Collaboration showed moderate evidence (three trials, 338 participants) that acupuncture is more effective than inactive treatment for pain relief for patients with chronic MND measured at short-term follow up. In the intermediate (3–12 months) and long-term follow-up categories (>12 months) in this Cochrane review, a single high-quality but underpowered study compared acupuncture with sham and showed no effect.

A cohort study by Blossfeldt (2004) showed an overall success rate of 68% of acupuncture for chronic neck pain, with success defined as 50% or greater improvement of pain at the completion of three or more treatments. However, the study was not blinded, had no formal inclusion or exclusion criteria, did not include a control group, and treatments were individualized rather than standardized. Although Blossfeldt’s study does not prove a treatment effect of acupuncture for chronic neck pain, it is an example of a relatively high level of self-reported patient improvement for a low-risk treatment. Of the 172 patients Blossfeldt treated, only two had complications, including one skin reaction and one migraine headache.

Acupuncture is a relatively safe modality for mechanical neck pain. A systematic review on the safety of acupuncture by Ernst and White 2001 showed the most common adverse events were needle pain (1%–45%), fatigue (2%–41%), and bleeding (0.03%–38%). The incidences of syncope and feeling faint ranged from 0% to 0.3%. Pneumothorax was rare, occurring only twice in nearly a quarter of a million treatments. Overall, acupuncture for mechanical neck disorders is relatively safe. Some evidence exists that it has a beneficial clinical effect for pain relief in the short-term. Further studies are needed to clarify the possible long-term effects and to examine which treatment strategies work best for various cervical conditions.

TENS

TENS, or transcutaneous electrical nerve stimulation, is the application of a pulsed electrical current through the skin to peripheral sensory nerves for the control of pain. Muscle contractions may occur as a side effect, although they are not the primary goal as in neuromuscular electrical stimulation. TENS is often applied via a portable unit consisting of a battery, signal generator, and electrodes. Currents are usually less than 100 mA with pulse rates ranging anywhere from 2 to 200 Hz. Placement of TENS electrodes is subjective, and painful sites, sites contralateral to the pain, nerves, trigger points, and even acupuncture points have been targeted.

The advantages of TENS include relative comfort, rapid-onset of therapeutic effect, capability for continuous and portable use, and applicability to a variety of pain conditions. The main disadvantages are the relatively short-duration and poor carryover of the treatment effects.

Serious complications from TENS are rare. Manufacturer-listed contraindications include pregnancy, cardiac pacemaker, and epilepsy. Electrode placement over the anterior neck should be avoided, as carotid sinus stimulation could lead to vasovagal hypotension and glottic or laryngeal nerve stimulation could lead to laryngospasm and airway occlusion. Electrode placement near active malignancy should also be avoided without caution due to promotion of cell growth by electrical currents in vitro. Electrodes should be placed over healthy, normal skin due to the risk of damaging frail skin or causing burns in insensate skin. Contact dermatitis may occur, and hypoallergenic electrodes are available. Driving or operating potentially hazardous equipment should not be done during TENS.

High frequency stimulation reduces pain by depolarizing type 1 afferents in muscle and skin which competes with signals from painful nerve endings per the Gate Theory of Pain. Low frequency stimulation (1 to 10 mA) is associated with the release of endorphins and serotonin.

The choice of frequency may be directed by the clinical diagnosis. For example, in a randomized, double-blinded, controlled trial of 32 subjects, Walsh and colleagues (1995) found that low-frequency TENS at 4 Hz was more effective in decreasing ischemically-induced pain than 110 Hz TENS, placebo, and no treatment. TENS at 2 Hz may be helpful for postoperative and radicular pain, although this intervention was not placebo-controlled.

Three trials reported immediate posttreatment pain relief when using TENS for chronic cervicalgia in comparison to sham controls. Frequencies varied from 60 to 143 Hz and schedules varied from 1 to 10 treatments. Various studies have examined the addition of TENS to other treatment modalities. Chiu and colleagues (2005) compared three groups consisting of infrared irradiation, infrared irradiation plus TENS, and infrared irradiation plus exercise. When infrared irradiation was combined with either TENS or exercise, subjects showed significant improvements in disability, isometric neck muscle strength, and pain scores. However, TENS was no more effective than exercise.

In another modality-combining study by Hou and colleagues (2002,) the use of TENS for cervical myofascial pain was examined. Treatment groups consisted of active range of motion exercises plus warm packs versus the former combined with TENS and either ischemic compression of myofascial trigger points or stretch and spray technique. The groups combining TENS and a myofascial release technique showed significant improvements in pain tolerance and visual analog scale pain scores.

Hendriks and Horgan (1996) studied the addition of Ultra-Reiz TENS at 143 Hz to a treatment regimen of ice, physiotherapy, postural education, and cervical collar use for patients with acute whiplash-associated disorders. The addition of Ultra-Reiz TENS to the treatments resulted in significant pain intensity reduction and improved cervical range of motion at the end of a 6-week treatment regimen. However, the outcome assessor may not have been blinded.

Nordemar and Thorner (1981) compared the effects of TENS, cervical collars, and manual therapy for acute cervical pain. Improvement was rapid in all groups, although TENS use led to more rapid restoration of cervical mobility. Farina and colleagues (2004) examined the effect of TENS at 100 Hz compared with frequency-modulated electromagnetic stimulation from 1 to 40 Hz (FREMS) and both were shown to be similarly effective at visual analog scale pain score reduction.

In a study by Escortell and colleagues (2010) patients with mechanical neck disorders were randomized to either TENS at 80 Hz or manual therapy (neuromuscular techniques, post-isometric stretching, spray and stretch, and Jones technique.) Both treatments resulted in greater than half of the patients having significantly reduced visual analog scale pain scores at short-term follow-up. Neither treatment was shown to be more effective. Success rates decreased to one-third of patients at a 6-month follow-up.

A recent Cochrane review by Kroeling and colleagues (2010) summarized the evidence for TENS for neck pain. This modality might be more effective than placebo, but has not been shown to be more effective than other interventions. When assessing the included trials, funding biases and small sample sizes were considered. The quality of available evidence, as per the review authors, was low to very low. It has been noted by other investigators that proper blinding of TENS for research purposes is difficult. Further research may change estimations of the effectiveness of TENS on cervical disorders.